Liquid crystal displays (LCD's) are commonly employed to display alphanumeric data obtained by electronic instrumentation in response to measured parameters, such as voltage, current, resistance, etc. A liquid crystal material is one which is birefringent and exhibits interference patterns and polarized light resulting from parallel orientation of large clusters of molecules. Depending upon the magnitude of voltage applied between parallel back plane and segment conductors characters are formed by light reflected from the particular segments upon which the display voltage is applied. Because LCD devices have a very high internal impedance, the current drawn by the devices is small making LCD's desirable for battery-operated instrumentation.
In compact instrumentation, the LCD is typically mounted on a printed circuit board having a conductive pattern for applying electrical signals to corresponding conductors on the surface of the LCD extending from the segment electrodes. The LCD is generally mounted directly on the printed circuit board using mounting bolts, screws or accessory pieces. There is often a critical alignment problem to ensure electrical coupling between the circuit board and LCD which must be taken into account when the LCD is screwed or bolted to the circuit board. LCD assembly time is thus substantial and it is difficult to subsequently disassemble the display for calibration or repair since access must be made to the locking elements which are typically at least partially located behind a front panel. Furthermore, there is a tendency for the mounting bolts or screws to loosen in response to shock or vibration; this problem commonly occurs in hostile environmental such as those to which cockpit-mounted instrumentation is exposed.
One object of the present invention, therefore, is to provide a new and improved device for mounting an LCD to a circuit board.
Another object is to provide a device for mounting an LCD to a circuit board without requiring mounting bolts, screws, accessory pieces or the like.
Another object is to provide a device for mounting an LCD to a circuit board wherein assembly and disassembly are simplified.
A further object of the invention is to provide a device for mounting an LCD to a circuit board that is shock and vibration resistant.
A still further object of the invention is to provide a device for mounting an LCD to a circuit board, the device being inexpensive to manufacture and convenient to install.
An additional object of the invention is to provide a new and improved LCD assembly that is easily assembled and disassembled and is shock or vibration resistant.
A still further object of the invention is to provide a new and improved LCD assembly that does not require mounting screws, bolts or necessary pieces for mounting.